7.1.1 Turn-on Delays

The timing of the turn-on transition has three components: propagation delay, turn-on delay and rise time. The first component is the propagation delay of the driver from when the input goes high to when the GaN FET starts turning on (represented by 1 A drain current). The turn-on delay is the delay from when the FET starts turning on to when the drain voltage swings down by 20 percent. Finally, the V_DS fall time is the time it takes the drain voltage to slew between 80 percent and 20 percent of the bus voltage. The drive-strength resistor value has a large effect on turn-on delay and V_DS fall time but does not affect the propagation delay significantly.